From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2ACCFC388F2 for ; Tue, 3 Nov 2020 01:22:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E2FB32063A for ; Tue, 3 Nov 2020 01:22:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604366554; bh=AzkNGzZcPAS3X/Z8RvdqSqjKNkUC0T4JNxfRrlDIuhY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=w7ORQgr4nGwubCizdiySiPdkQ8Y0EmYlu4Phdo2rdoKNxoVsI9jjpixbe7uBvokiz 6MlYiD3G1WKCoaKrn1gZCNVe+GBEO5yREAF0Behoginq3uOcldL3PoI2qy3DiIo+lP hshrscWpJyckCwu3iAT1T7gQUOEDKv8xhUR11ZKk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728306AbgKCBVB (ORCPT ); Mon, 2 Nov 2020 20:21:01 -0500 Received: from mail.kernel.org ([198.145.29.99]:36204 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728283AbgKCBU6 (ORCPT ); Mon, 2 Nov 2020 20:20:58 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 15A1222450; Tue, 3 Nov 2020 01:20:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604366457; bh=AzkNGzZcPAS3X/Z8RvdqSqjKNkUC0T4JNxfRrlDIuhY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=S8+N3keWeye6p7woidTIBWvUou+d4hZ7+FPnQZqARE06ZusjfB5M6ETq7TmgzmGov zN5xtFQwkCndxwVlKsEnldSa318mO3pf01h6j4WHMW3bUbdHCw8riJHf/fKJ2YHTmR k+hZ/8HAOSrbqZWZ6EjlhAxVhc0oaPOsCdwsKmsU= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Kairui Song , Ingo Molnar , Sasha Levin Subject: [PATCH AUTOSEL 4.14 02/10] x86/kexec: Use up-to-dated screen_info copy to fill boot params Date: Mon, 2 Nov 2020 20:20:46 -0500 Message-Id: <20201103012054.183811-2-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20201103012054.183811-1-sashal@kernel.org> References: <20201103012054.183811-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kairui Song [ Upstream commit afc18069a2cb7ead5f86623a5f3d4ad6e21f940d ] kexec_file_load() currently reuses the old boot_params.screen_info, but if drivers have change the hardware state, boot_param.screen_info could contain invalid info. For example, the video type might be no longer VGA, or the frame buffer address might be changed. If the kexec kernel keeps using the old screen_info, kexec'ed kernel may attempt to write to an invalid framebuffer memory region. There are two screen_info instances globally available, boot_params.screen_info and screen_info. Later one is a copy, and is updated by drivers. So let kexec_file_load use the updated copy. [ mingo: Tidied up the changelog. ] Signed-off-by: Kairui Song Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20201014092429.1415040-2-kasong@redhat.com Signed-off-by: Sasha Levin --- arch/x86/kernel/kexec-bzimage64.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c index 4d948d87f01cc..a65636d60296c 100644 --- a/arch/x86/kernel/kexec-bzimage64.c +++ b/arch/x86/kernel/kexec-bzimage64.c @@ -211,8 +211,7 @@ setup_boot_parameters(struct kimage *image, struct boot_params *params, params->hdr.hardware_subarch = boot_params.hdr.hardware_subarch; /* Copying screen_info will do? */ - memcpy(¶ms->screen_info, &boot_params.screen_info, - sizeof(struct screen_info)); + memcpy(¶ms->screen_info, &screen_info, sizeof(struct screen_info)); /* Fill in memsize later */ params->screen_info.ext_mem_k = 0; -- 2.27.0